Yes actually. I had originally planned to have 2 Side Characters that would help the Protagonist of my Story, Mi'kael on his Journey. Being sort of the emotional support for him, for better or worse, also being the ones that sort of pull him out of his thirst for vengeance.
However, in the Original Draft, they were pretty irrelevant, extremely shallow and had no sort of uniqueness to them. They were nothing more than Side Character A and Side Character B, one being a sort of comedic relief while the other being the 2nd Half of the Brains in the team.
Once I re-read my draft, I realised how badly written they were, and essentially left drafting for a bit to fully realise those characters as unique individuals with their own pursuits and their own goals. Not just exisiting for the sake of changing the Protagonist, but the Protagonist being the catalyst for them to change.
Unique Goals, Unique Apperances, and Unique reasons for doing what they do.
Out of them all, the one I instantaneously fell in love with was Eryn Myrr.
He was easily one of the most amazing characters I'd say I had created, to the point that many of my beta readers, and some of my current readers ended up falling in Love with him. Literally and Figuratively too lmao.
My obsession with him has gotten so high to the point that I'm considering creating a Standalone Prequel for him in the Future, and currently? my artist friend and I are designing a piece of him lol.
Eryn Myrr and the other Character, Nero Seraphane, are now Important Characters to the story, that will impact the Future of the Series too!

I friggin love this guy.